drm/edid: parse ycbcr 420 deep color information

CEA-861-F spec adds ycbcr420 deep color support information
in hf-vsdb block. This patch extends the existing hf-vsdb parsing
function by adding parsing of ycbcr420 deep color support from the
EDID and adding it into display information stored.

V2: Rebase
V3: Rebase
V4: Moved definition of y420_dc_modes into this patch, where its used
    (Ville)
V5: Optimize function, if(conditions) not reqd (Ville)
V6: Rebase
V7: Rebase

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1499960000-9232-8-git-send-email-shashank.sharma@intel.com
[vsyrjala: Fix sparse indentation warn]
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

drivers/gpu/drm/drm_edid.c

@@ -4202,6 +4202,16 @@ drm_default_rgb_quant_range(const struct drm_display_mode *mode)
 }
 EXPORT_SYMBOL(drm_default_rgb_quant_range);
 
+static void drm_parse_ycbcr420_deep_color_info(struct drm_connector *connector,
+					       const u8 *db)
+{
+	u8 dc_mask;
+	struct drm_hdmi_info *hdmi = &connector->display_info.hdmi;
+
+	dc_mask = db[7] & DRM_EDID_YCBCR420_DC_MASK;
+	hdmi->y420_dc_modes |= dc_mask;
+}
+
 static void drm_parse_hdmi_forum_vsdb(struct drm_connector *connector,
 				 const u8 *hf_vsdb)
 {
@@ -4242,6 +4252,8 @@ static void drm_parse_hdmi_forum_vsdb(struct drm_connector *connector,
 				scdc->scrambling.low_rates = true;
 		}
 	}
+
+	drm_parse_ycbcr420_deep_color_info(connector, hf_vsdb);
 }
 
 static void drm_parse_hdmi_deep_color_info(struct drm_connector *connector,

include/drm/drm_connector.h

@@ -154,6 +154,9 @@ struct drm_hdmi_info {
 
 	/** @y420_cmdb_map: bitmap of SVD index, to extraxt vcb modes */
 	u64 y420_cmdb_map;
+
+	/** @y420_dc_modes: bitmap of deep color support index */
+	u8 y420_dc_modes;
 };
 
 /**

include/drm/drm_edid.h

@@ -213,6 +213,14 @@ struct detailed_timing {
 #define DRM_EDID_HDMI_DC_30               (1 << 4)
 #define DRM_EDID_HDMI_DC_Y444             (1 << 3)
 
+/* YCBCR 420 deep color modes */
+#define DRM_EDID_YCBCR420_DC_48		  (1 << 6)
+#define DRM_EDID_YCBCR420_DC_36		  (1 << 5)
+#define DRM_EDID_YCBCR420_DC_30		  (1 << 4)
+#define DRM_EDID_YCBCR420_DC_MASK (DRM_EDID_YCBCR420_DC_48 | \
+				    DRM_EDID_YCBCR420_DC_36 | \
+				    DRM_EDID_YCBCR420_DC_30)
+
 /* ELD Header Block */
 #define DRM_ELD_HEADER_BLOCK_SIZE	4